group calendar is not created, impossible to find it, you can reproduce this.
Once you create a Team via Teams, it would also create a group mailbox with calendar, while by default it is hidden.
Please refer to this link: How Microsoft 365 Groups work with Teams
You may connect to Exchange Online Powershell with an account with the required permissions (Exchange admin or Global admin) to run the following cmdlet to enable it:
Set-UnifiedGroup -identity <group name> -HiddenFromExchangeClientsEnabled:$false
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